The present invention relates to water circulation and filtration apparatus, and particularly to such apparatus as used in swimming pools. A turbine device is provided on the bottom of the pool and is run by a flow of water, for example, the suction flow to a water filtration pump. The turbine device includes a first turbine, i.e., an impeller which circulates water from the bottom of the pool to the surface in a continuous stream. The continuous stream carries with it any large debris which may have accumulated in the pool. A second turbine is mechanically connected to the first turbine and is rotated by the flow of water. The invention also provides for a unique arrangement which excludes debris from the first turbine.
A major problem associated with the maintenance of swimming pools, particularly outdoor pools, is the removal of debris such as dirt, leaves, trash and the like, which can accumulate both on and below the water surface as a result of normal use. To remove such debris, the pool is usually provided with a circulation pump and filter system, the filtration being effected by passing a stream of water from the pump discharge through one or a series of filters and thereafter returning the filtered stream to the pool.
This type of filtration is generally adequate for removal of small debris particles. Care must be taken, however, to prevent entrainment of large debris into the pump suction, as this can result in damage to the pump and/or clogging of the filter system. Large material is therefore excluded from the pump suction stream through a grating or like structure at the stream entrance.
Two problems are associated with this arrangement. First, large pieces of debris may adhere to the suction stream grating, thereby excluding flow to the circulation pump. Second, the large debris must be removed from the pool through some external means, such as manual skimming of the water surface. Manual skimming is, however, a time consuming procedure. Further, skimming does not provide for recovery of large debris which cannot be brought readily to the water surface, that is, debris having a neutral or negative buoyancy.